40-65: Learning what I can

[SgtDog0311]

Thanks Don... the expander in the Cowboy dies is .4065. The top of the expander should give enough flair I'd think. What I was thinking may present an issue were dies that did not match the chamber. I read this last night:
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" The unique features of the Browning .40-65 chamber, which differentiates it from the classical .40-65 Winchester design, is the cylindrical area just ahead of the case rim and a well defined neck. In contrast to Winchester’s original .40-65 cartridge design, there’s no taper or change in chamber diameter in the first 0.135” of the case region in front of the rim. Also, the final 0.500” section is a cylinder with a constant diameter, a region that can clearly be defined as a neck. Some reamer suppliers are listing the chamber dimensions as the .40-65 Browning. I understand that Lyman's .40-65 die set was designed to match the Browning chamber, although others may also. I have the Lyman and can verify that it does".
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I'd think full length resizing with a die barrel that didn't match the chamber might be an issue. Of course I'd be neck sizing ultimately but would want the full-length to be correct nonetheless.

I'd fall in that category of "thinking everything to death"; probably just a function my nature and of money being hard-to-come-by so trying to avoid any do-overs. The 40-65 is unfamiliar territory for me so I'm just wanting to make sure I'm understanding the varieties of 40-65 chambers.

Also realize I'm complicating things a good deal by being hard-over on a flat transition.